(1) Field of the Invention
The present invention forms part of the building field and, more specifically, concerns a casing with enhanced thermal insulation capacity for openings, such as windows, doors, facades and the like, belonging to any building.
More precisely, the present invention concerns a casing with enhanced thermal insulation capacity of the so-called “closed-joint” type, that is provided with double gaskets positioned one on the outer side and one the inner side, in the ledge section bars of the casing.
The casing comprises welded or open tubular section bars, as well as a reference counter-frame and one or more finishing elements.
(2) Description of the Related Art
As known, there are, for a long time on the market of the field here, relevant casings or frames for closing openings of buildings which are able to keep, in a more or less effective manner, conditions of thermal insulation inside the environment delimited by the perimetrical walls in which the casing is mounted. Indeed, one of the main technical features required for the casings is a high thermal insulation capacity against atmospheric agents, such as air, wind, and water which inevitably affect the casings.
Moreover, another important property required for the casings is the capacity to acoustically isolate the environments or the rooms of buildings from noises coming from the outside, which noises may disturb the normal and customary work, recreational and/or relaxation activities of the people inside.
In addition to these prerogatives, the casings must however present other constructive features, such as allowing the entry of light in case they are of the type that can be opened and moved by the user without particular difficulties or hindrances. The casings must also have structural strength and non-deformability against the action of the atmospheric agents when subjected to continuous opening and closing cycles. The casings must also assure a perfect tightness in closing conditions and discourage or effectively prevent acts of vandalism.
The casing or frames made of wood are notoriously easy to build and present a remarkable capacity for thermal insulation, due to the inherent insulating properties of wood.
However, considering the increased requirements related to the sizes of the casings and, more in detail, the shape of the panels, especially if made of glass (which is more and more thick and heavy in order to assure adequate insulation and mechanical strength), when mounted on the perimetrical section bars, the casings are often made of wood and/or metallic material such as aluminium and/or steel, as well as wood and/or plastic material such as polyvinylchloride (PVC).
These casings for openings of buildings typically comprise a first tubular section bar made of metallic material, for instance steel, which is fixed to the perimetrical wall delimiting the opening, and a second metallic tubular section bar, cooperating with the first section bar in order to close the opening and supporting one or more front panels of an interface between the outer environment and the inner environment of a room inside a building.
The tubular section bars present good mechanical strength against the atmosphere agents, especially when used to support large glass slabs in casings of relevant sizes, by virtue of the structural strength and non-deformability afforded by the metallic material with which they are made.
Nevertheless, these metallic tubular section bars of the casings of the known type do not have the necessary thermal insulation characteristics.
In order to remedy such a problem, metallic casings have been proposed on the market for some years, commonly known in the field as “thermal break casings”, which include an element made of low thermal conductivity material interposed between the outer tubular section bar and the inner tubular section bar. Such a thermally insulating element limits the heat transfer from the inner environment to the outside, thereby avoiding the formation of thermal bridges, usually along the perimeter of doors and windows.
On the other hand, the aforesaid thermal break casings present the recognized drawback of being subject to the so-called “bimetal effect”: the outer tubular section bar and the inner tubular section bar, being at temperatures which differ from each other, inevitably suffer non-homogenous thermal expansions which cause dangerous deformations of the section bars themselves, especially if the bars are made of aluminium, since, as known, this material is an excellent heat conductor. This drawback limits at least partially significantly the air-tightness properties of the casings in closing conditions, thereby causing, on one hand, problems of heat dissipations, and on the other hand, phenomena of infiltration, responsible for the formation and proliferation of molds and other bacterial colonies. This drawback also causes a drastic reduction in the level of acoustic insulation of rooms inside the building.
The constructive solution nowadays widely adopted is the interposing of an insulating material element in a central section of the casings, between the two tubular section bars which compose it. This solution considerably reduces, therefore, the mechanical strength characteristics of the section bars in question.
One should not forget also that some plastic components present toxicity issues which arise during the process of welding the section bars. Welding is an essential process to assure section bars proper structural stability over time.
For the plastic components, in addition, polluntion pollution issues arise relating to the disposal of working scraps and, last but not least, to the dismantling phase of the casing, at the end of the operating cycle.
Furthermore, in some cases, for the type of application to which they are intended, the tubular section bars of the casings should be properly subjected to a process of glazing by which, notoriously, a mechanical part is smoothed, deburred, polished and/or furbished.
In case of traditional thermal break casings, however, such a process of glazing cannot be completed since, by providing a significant pressure on the metallic tubular section bar, the process would seriously compromise the connection between the insulating material element and the tubular section bar.
German prior art document 2129779 discloses a casing for openings of buildings of the so-called “open-joint” type, wherein the outer tubular element, produced by aluminium drawing, presents a plurality of through openings simply having the aim to discharge water which accumulates or condensate which is produced inside the drawn tubular element.